A substrate for growth, on which epitaxial layers are grown during epitaxial growth, is placed on a disc-like susceptor, for example. The susceptor has a plurality of through-holes formed penetrating through the front and rear surfaces thereof, and as disclosed in Patent Document 1, for example, a lift pin is inserted in each through-hole, and the lift pin is vertically movable with respect to the susceptor. The vertical movement of the plurality of lift pins inserted in the respective through-holes enables transfer of a wafer between the lift pins and the susceptor.
When a wafer transferred above the susceptor is placed on the susceptor, the plurality of lift pins are caused to project upward from the through-holes, and the wafer is received such that the rear surface thereof is supported by the upper surfaces of the projecting lift pins. Then, the lift pins, supporting the wafer, are moved downward to lower the wafer on the susceptor, whereby the wafer is placed on the susceptor. The lift pins, which have placed the wafer on the susceptor, are suspended such that the upper surfaces thereof retract into the through-holes, and the upper edges thereof are caught by the through-holes. Thereafter, epitaxial layers are vapor-phase grown on the wafer placed on the susceptor.
During the epitaxial growth, the wafer is heated by heat sources located above and beneath the susceptor. The heat that heats the wafer is also transmitted to each lift pin, the upper edge of which is caught by the through-hole of the susceptor, and heat dissipation or the like from the lift pin occurs during the epitaxial growth, which causes a difference in temperature between the area around the lift pin and other areas. Therefore, in the susceptor and the wafer during the epitaxial growth, a local temperature difference may occur in an area depending on whether or not the area is near the lift pin. If the epitaxial growth proceeds with such a temperature difference, flatness of each epitaxial layer is deteriorated.
Hence, the temperature difference caused by the lift pins is suppressed by adjusting the balance of outputs of the heat sources located above and beneath the susceptor, thereby to make the surface of each epitaxial layer flat.